Individual differences in the development of youth externalizing problems predict a broad range of adult psychosocial outcomes.

This study examined how youth aggressive and delinquent externalizing problem behaviors across childhood and adolescence are connected to consequential psychosocial life outcomes in adulthood. Using data from a longitudinal, high-risk sample (N = 1069) that assessed children and their parents regularly from early childhood (ages 3-5) through adulthood, multilevel growth factors of externalizing behaviors were used to predict adult outcomes (age 24-31), providing a sense of how externalizing problems across development were related to these outcomes via maternal, paternal, teacher, and child report. Findings indicated strong support for the lasting connections between youth externalizing problems with later educational attainment and legal difficulties, spanning informants and enduring beyond other meaningful contributors (i.e., child sex, cognitive ability, parental income and education, parental mental health and relationship quality). Some support was also found, although less consistently, linking externalizing problems and later alcohol use as well as romantic relationship quality. Delinquent/rule-breaking behaviors were often stronger predictors of later outcomes than aggressive behaviors. Taken together, these results indicate the importance of the role youth externalizing behaviors have in adult psychosocial functioning one to two decades later.